Reference is made to U.S. Pat. No. 4,520,664 issued June 4, 1985 wherein there is disclosed a valve cap pressure drop indicator. Reference is also made to a U.S. Pat. No. 4,606,391 wherein there is disclosed a visual pressure drop indicator.
The present invention is directed to an improvement in construction of an in situ pressure indicator which is of simple construction, more easily sealed for long life use, and readily assembled.
Additional objects and features of the invention will be apparent in the following description and claims in which the principles of the invention are set forth together with details to enable persons skilled in the art to practice the invention, all in connection with the best mode presently contemplated for the invention.